A certificate of analysis is a document reporting what a laboratory found when it tested a specific production lot of a specific material.
That definition is doing a lot of work, and most of what circulates in this category under the name does not meet it. The difference is one column, and it is the most useful thing anyone can learn about supplement paperwork.
What is a certificate of analysis?
A report of test results on a named lot of material. A complete one names the material, the lot, the date, each test performed, the method used, the specification each test was measured against, and the result the test returned. It is issued by whoever ran or commissioned the testing, and it is signed.
Read that list again and count how many of those items appear on a document a supplement brand has sent you. The gap between the definition and the shelf is where this entire subject lives.
What is the difference between a specification and a result?
A specification is what a formula is supposed to be. A result is what a test found. A specification sheet lists limits — lead below three parts per million, identity above 95% — and stops. A certificate of analysis lists those same limits and then prints, beside each one, the number that came back.
Both documents are useful and only one of them is a measurement. A specification-only sheet describes an intention. A result describes an event. The category calls them both certificates, which is how a document that measured nothing ends up being cited as proof.
What should be checked on a certificate?
Six things, in this order. Whether there is a result column or only a limits column. Whether a lot number is printed. Whether a method is named beside each test. Whether it carries a date. Who issued it, and whether a laboratory is named. And whether it says what it did not test.
- Is there a result column, or only a limits column? This decides everything else.
- Is a lot number printed? A document with no lot is not about any particular material.
- Is a method named beside each test? A percentage without a method is not comparable to another percentage.
- Is there a date? Both a test date and a document date, ideally.
- Who issued it, and is a laboratory named? Many documents in this category are issued by the manufacturer and name no laboratory at all.
- Does it say what it did not test? The strongest documents do. Almost none do.
What do TARE's own certificates report?
Two of our four report measured results. Two report specification limits and no test results at all. That is stated at the top of every panel rather than covered by one word. First Food, lot R506064, reports an FT-IR identity assay at 98.5% against a greater-than-95% specification and lead at 0.005 ppm against a less-than-3 ppm limit. Night Work, lot MGL250923, reports magnesium at 96.91 mg per capsule against a greater-than-91.6 mg specification.
That second one is the strongest thing this company owns and it is worth spelling out. Our serving is three capsules, so the measured serving is 290.7 mg of elemental magnesium against the 275 mg the label claims. We claim less than the document found, and we publish both figures.
Training Water, lot 5120130, and Mineral Base, lot 6010323, set out composition and limits and report no measured result, no method and no test date. We say which two are weaker rather than averaging four documents into one adjective. Every row of all four is transcribed on Testing & Certification.
Where our own documents stop
No laboratory is named on any of the four. First Food’s rows identify one only as Lab ID: 1. Whether that laboratory sits inside the manufacturer or outside it, and what recognition it holds, are open questions we have put to the manufacturer and have not had answered. Until they are, we attach no testing descriptor to this brand at all and print the numbers instead.
Every certificate names the lot it was run on, and it is not the reader’s lot. That distinction is not a technicality. Naming a lot is exactly what separates a real document from a marketing PDF — and TARE is made by a contract manufacturer and never takes possession of inventory, so nothing connects a published lot to the jar in anyone’s hands. We publish the document, name the lot on it, and do not claim it is yours.
The files themselves are not published yet. Each carries a line requiring the manufacturer’s written approval before reproduction, and that approval has not arrived. The figures are published because a measured result is a fact about a quantity of powder; the documents go up when the answer does.
What a certificate cannot tell you
It cannot tell you whether a formula works. A certificate is a composition and contamination document. It answers what is in the material and how much, and it is silent on every question about outcome. A brand using a certificate as evidence for a benefit is using the wrong document, confidently.
It cannot tell you the material in your jar is the material on the paper. See above. Anyone promising that is promising something a contract-manufactured supply chain does not deliver.
And the test worth running on any brand, including this one: ask for the document, then read the result column. Almost nobody in this category publishes one at all, and nobody publishes one showing they claim less on the label than the assay found. That comparison takes ten seconds and it is the whole of what we are asking anyone to do.
More in this cluster: what a GMP claim actually covers, the format that makes the arithmetic impossible, and the sixty-second label procedure.